Cut an identifier at blank/space after dot.

[cristianoc]

Since the parser allows space after ".", some autocomplete user intent can get lost.
For example:

type record = {
  someProp: SomeModule. // <-- cursor
  otherProp: string,
}

The parser will parse as SomeModule.otherProp then error on the ":" token.
The autocomplete engine now recognises these situations and splits up SomeModule.otherProp, which is provided by the parser's AST, into SomeModule..